The invention relates generally to the field of internal combustion engines designed to use different fuels having different combustion properties. More particularly, embodiments of the present invention relate to a high viscosity fuel injection pressure reduction system and method that may be implemented for using alternate fuels in engines such as diesel engines.
Internal combustion engines are used for many different applications, including the generation of electrical power and the propelling of vehicles over land and sea. Electrical generator sets may be used in a variety of such applications to generate power used in various loads, including the driving of electric motors in vehicles such as locomotives, sea-going vessels, and so forth. Such internal combustion engines may include diesel engines that are configured to operate with a specific type of diesel fuel. For example, the commercial marine industry has developed tailored marine fuels that are more cost effective for the diesel engines used in marine applications. Moreover, the types of diesel fuels and their physical properties may vary from industry to industry. In addition to operating on such varied diesel fuel standards, some engines may be called upon to operate on other types of fuels, such as various combustible oils.
Poor engine performance or engine damage may result if the wrong type of diesel fuel is used in a diesel engine not designed to operate on such fuels. For example, using a marine diesel fuel in a locomotive application may increase peak injection pressures within the injection system because of the higher viscosity of the marine diesel fuel. However, it may indeed be desirable to configure a diesel engine so that it may be implemented in either application (i.e., a railroad locomotive or a marine vessel). One method for reducing the injection pressure within the fuel injection system is to pre-heat the fuel to reduce its viscosity. However, components for pre-heating the fuel take up valuable space and increase the weight of the vehicle. Additionally, pre-heating is a somewhat delicate process that increases the cost and complexity of the engine system. There is a need in the art for approaches to engine design and configuration that permit different fuels to be utilized on particular engines while respecting injection pressure and other design parameters.